Attempts at prophylaxis for murine Pneumocystis carinii pneumonitis

The prevalence of P. carinii has increased in the United States within recent years. Patients at high risk for this infection can be identified on the basis of their primary diseases. An effective method for prevention of P. carinii infection is needed. Sprague Dawley rats immunized with P. carinii or treated prophylactically with pentamidine or pyrimethamine and sulfadiazine were not protected from fatal P. carinii pneumonitis when subjected to corticosteroid therapy.